Iowa: License Plate Blockers Produced Mixed ResultsA television station in Iowa puts license plate blockers to the test.

Products that cover license plates and are designed to defeat red light cameras and speed cameras yielded mixed results in a test this week by KCCI-TV in Des Moines, Iowa. With the help of Clive police and the city's red light camera system, the station tried two types of plate cover and PhotoBlocker spray.

The test used a police cruiser equipped with each plate cover driving through an intersection temporarily blocked off to traffic. Tests were done during the day and repeated at night.

According to KCCI, the plate cover designed to make a license plate more reflective failed entirely to distort the red light camera photograph. The PhotoBlocker spray only made it difficult to distinguish between a "B" and an "8" on the plate at night. The PhotoShield cover, however, succeeded in making the plate difficult for the camera to read both during the day and at night. The downside to this plate cover is that it police in Clive say they would issue a $63 ticket to anyone caught using it.